As a large-capacity nonvolatile memory, a two-terminal resistance change type memory can be implemented in place of a floating gate type NAND flash memory. With this type of memory, low voltage/low current operation, high speed switching, miniaturization and high integration of memory cells are possible.
In a large-capacity memory array, a large number of metal wirings called bit lines and word lines are arranged in a crossing manner, and a memory cell is formed at the intersection of each bit line and each word line. Writing to one memory cell is performed by applying voltage to the bit line BL and the word line WL connected to the memory cell.